Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to an assembly jig for
manufacturing a long structure with an arcuate cross
section such as a roof construction of railway carriages
eta and more specifically to an adjustable jig with
curved surfaces.
Description of the related Art
The long structure like a roof construction of
a railway carriage is generally constructed from a roof
board, cross members, and longitudinal members, and has
generally an arcuate cross section. The Conventional
methods for manufacturing such a construction require
therefore the use of an assembly jig comprising a curved
jig with an arcuate cross section. For example, the roof
construction of the railway carriage is made by the steps
of placing, on the concave surface of the jig, thin steel
sheets in parallel side by side, welding them to each
other, laying down a roof framing of the steel sheets,
and welding or tack welding the roof framing to the steel
sheetsO
The manufacture of various roof constructions
with arcuate cross sections of various radii of curvature
requires various special assembly jigs for different
roof constructions Therefore, the assembly jigs have to
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l be replaced for different one before conducting another
assembling cf different roof constructions.
The conventional curved jigs thus suffer from
the following disadvantages
(a) The curved jigs have to be replaced for another
one for the different roof construction with a different
cross section.
(b) Since the curved jigs used in this kind of work
are very heavy, an overhead travelling crane or a fork-
lift truck has to be used to move them in the replacement
operation.
(c) Since the curved jigs are made of thick steel
plates, it is difficult and time-consuming to shape this
thick steel plates to the curvature required
td) During welding of steel sheets on the curved
jig to form a roof board, the heat of the welding might
cause distortion in the shape of the curved jigs, with a
resultant loss of precision of the curved jig.
(e) Where various curved jigs with different
curvatures are prepared in advance, they require a wide
storage space. On the other hand, where the curved jig
is made up specially at each time, it takes up a great
deal of time.
(f) Since the curved jigs are made up from a plurality
of steel plates welded to each other end to end, the
longitudinal alignment is poor, which in turn means the
overall shape of the product roof construction is not good.
(g) An exchange of the curved jigs requires much
1 time and hard labor.
SUMMARY OF THE INVENTION
In the light of this situation, this invention
is intended to overcome the problems of the conventional
art hy providing a simple yet rational means for
eliminating the need for replacing the curved jig for
another one, such means ofering a crane-less, economical,
quick change-over and safe operation and a product of
high quality.
In order to overcome the problems inherent in
the conventional art, this invention proposes an
adjustable jig with curved surfaces which comprises a
plurality of rails arranged parallel to constitute a curved
surface, a device for linking the rails, a device for
lifting the rails, at least one foot attached to each of
the rails, at least one pedestal prepared for each of the
rails and supporting the foot of each of the rails, and a
device for shiEting the pedestals.
The invention offers the following advantages:
(a) Work required to alter the curvature of the
adjustable curved jig to fit new specifications can
easily be done by a single operator in the minimum time.
(b) The invention completely eliminates the need for
the preparatory work which in the conventional art, is
required in replacing the assembly jig for another one.
(c) The adjustable jig can be adjusted to the
desired curvature simply by selecting the appropriate step
1 of the pedestal, or by replacing the pedestal for another
oneO
(d) There is no need to use a crane or a fork lift
truck in changing the curvature of the curved jigs.
(e) Complete safety is assuxed in changiny the
curvature of the curved jig, since no heavy objects have
to be moved.
(f) Unbroken rails are used fvr defining the long
jigs, as distinct from the joined sheets in the conventional
art, resulting in greater precision of the longitudinal
alignment and in improved quality cf the productsO
(g) The heat of the welding less affects the curved
jig, since the separate rails are used as distinct from
the conventional art using an integral wlded surface palte.
Thus, the precision of the curved jiy is maintained and
the quality of the product is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view showing the con-
ventional jig with curved surfaces;
Fig. 2 is a perspective view showing a part ofthe same jig shown in Fig. 1 as used in the assembling
of a long structure with an arcuate section;
Fig. 3 is a plan view of an adjustable jig with
curved surfaces of the invention;
Fig. 4 is a front elevational view of the
adjustable jig shown in Fig. 3;
Fig. 5 is an enlarged side elevational view of
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1 the adjustable jig shown in Fig. 3;
Fig. 6 is a side elevational view of a lifting
device of the adjustable jig shown in Fig. 3;
Fig. 7a is a perspective view of an essemtial
portion of a shifting device for pedestals of the
adjustable jig shown in Fig. 3;
Fig. 7b is a view similar to Fig. 7a, showing
modified pedestals of the adjustable jig;
Fig. 8 is an enlarged perspective view of part
of a roof construction during assembling operation using
the adjustable jig shown in Fig. 3;
Fig. 9 is a plan view of the adjustable jig
in which cooling water is supplied through the central
rail; and
Fig. 10 is a perspective view of an essential
portion of the adjustable jig shown in Fig. 9.
DE5CRIPTION OF THE PREFERRED EMBODIMENTS
Before going on to describe embodiments of
the invention, the conventional jig for curved surfaces
will be explained with specific reference to Fig. 1
and 2.
Fig. 1 shows a base 1 supporting the whole
structure. On the base 1 are placed supports 2, 3 length-
wise along the left and right sides and the center. Onthe supports 2, 3 is supported a curved surface plate 4.
This curved surface plate 4 consists of a plurality of
steel plates joined togehter end to end and shaped to
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76
l the appropriate curvature for the roof construction to
be mode
Fig. 2 shows the curved jig in use. Roof
boards 5a, 5b are lined up lengthwise side by side
along the curved surface plate 4 and are welded together.
A roof framing 6 is placed on the roof boards 5a, 5b
and welded to them.
The conventional curved jig shown ln Fig9 .
1 and 2 has the several disadvantages, as already
mentioned in the Description of the Related Art.
The invention will now be described in detail
with reference to Figs. 3 to 10.
This new curved j ig comprises a plurality
of rails ll including a central rail 12 which consti-
lS tutes the central part of the jig. The rails 11,12 àre disposed in parallel lengthwise as shown in Fig.
3.
The rails ll are designed to be movable so
that the curved jig can be adjusted to the desired
curvature, with the central rail 12 being
stationary to form a stationary central part of the
jig. The curved surface plate comprises links 13
to hold the rails ll, 12 together to prevent separation
of the rails. The links 13 are connected to feet 14
of the rails ll through pins to allow free movement of
the rails to any desired curvatures. Pedestals 15, 16,
17, 18 are provided to support the feet 14 ox the rails
ll. Each of the pedestals comprises a plurality of steps
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1 15a, 16a, 17a, 18a to permit the upper surface of
the rails 11 -to be adjusted to the required curva-
ture. By placing the feet 14 on the appropriate steps
15a-18a of the pedestals lS-18, the upper surfaces of
the rails 11, 12 can be adjusted to form a curved surface
with a good precision as shown in Fig. 5. Although the
pedestals 15-18 may be integrally made to form a single
body, it is better from the point of view of their
manufacture and replacement that they are made separate
as best shown in Fig. 5. The steps 15a-18a of the
pedestals 15-18 comprise inclined upper surfaces sloping
downward toward the central rail 12 so as to form a
concave curved surface as a whole with a good precision.
The steps 15a-18a, however, may comprise inclined upper
surfaces sloping upward toward the central rail 12 so
as to form a convex curved surEace as a whole. It is
to be noted also that, insteadly of having a number of
steps, the pedestals may have continuous inclined surface
lSa', see Fig. 7b, so that the curvature of the rails can be
adjusted continuously. However, with this modification
a long time would be required to adjust the position of
the pedestals Therefore, in practice the embodiment
shown in Fig. 5 is most preferable.
The pedestals 15-18 are mounted on a framework
19, which in turn rests on a base 20 through slide
bearings 21 so that the pedestals can be shifted
lengthwise along the jig i.e. along the axes of the
rails 11, 12.
1 Fig. 6 shows a lifting device A for lifting
all the rails 11 together so that the pedestals 1S-18
can then be moved freely along lengthwise of the curved
surface plate in the curvature changing operation. The
lifting device A is operated by hydraulic or pneumatic
cylinders 22 which raise up two levers 24 hinged at a
fixed center 23. The two levers 24 raise the rails 11
up all at a time to separate the feet 14 of the rails
11 from the pedestals 15-18. Next, the framework 19 on
which the pedestals 15-18 are mounted are shifted
lengthwise to a desired position. Finally, the cylinders
22 are contracted to have the feet 14 of the rails 11
rest on the desired steps 15a-18a of the pedestals 15-18V
whereby the curved jig has the aimed curvature.
Fig. 7 shows a shifting device B Eor shifting
the pedestals 15-18 lengthswise of the curved jig.
The shifting device B has a connecting bar 25
which interconnects the frameworks 19 holding the
pedestals 19-18 in position. On part of the upper surface
of the connecting bar 25 is secured a rack 26 which
meshes a pinion 27 whose shaft 28 is supported in a
holder 29. The shifting device B is operated by rotating
a wheel 30 attached to the end of the pinion shaft 28.
All of the pedestals 15-18 are shifted by rotating the
wheel 30 throught he action of the pinion 27, rach 25
and connecting bar 25.
If required, the curved jig may be
provided with separate shifting devices for respective
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1 rails 11 so as to use the different steps for different
pedestals to form any desixed shapes of the curved
jig.
Fig. 8 shows the adjustable curved jig in
use. Roof boards 3la, 3lb are placed in parallel
on the adjustable rails adjusted to have the
desired curvature. the roof boards 3la, 3lb are
welded to each other, the welding portion being on the
central rail 12. A roof framing 32 is placed on the
roof boards Finally, the roof framing 32 is welded to
the roof boards to complete the roof construction.
Further, the adjustable curved jig may be used for
assembling the roof framing per se. That is, roof
framing members are placed at desired positions on
the adjustable rails and welded or fastened to each
other to complete the roof framing 32.
Figs. 9 and 10 show a modification of the
embodimetn ox the adjustable curved jig. The central
rail 12, above which the two roof boards 31a, 31b
are to be welded to each other, is formed of a hollow
piece. Water pipes 33 are connected to the central rail
12 to supply cooling water to it, so that the heat
generated by the welder 35 as the roof boards 31a, 31b
are welded can be transmitted outside. Thus, less heat
affects the central rails 12 and the roof boards 31a,
31b.
The embodiment of the invention has been
explained for the roof structure of the railway carriages.
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1 The invention, however, is not exclusive and the inven-
tion may be applied to the assembling of other structures
having a partly arcuate cross section such as the side
structure of railway carriages etc.
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